Sipping Tarantula Venom Kills Crop-Eating Insects

Below:

Next story in Science

The venom in a tarantula's fangs packs a lethal punch when
injected into its prey.

But the toxic brew could also serve as an insecticide against
agricultural pests that consume the venom orally, a new study
finds. A component of the
spider venom is especially effective against the cotton
bollworm, a pest that attacks crop plants.

Globally, insect agricultural pests reduce crop yields by 10
percent to 14 percent and damage 9 percent to 20 percent of
stored food crops. Farmers primarily use chemical insecticides to
control pests, but many insects are resistant to them.

In the study, researchers milked venom from Australian tarantulas
(Selenotypus plumipes), and isolated a small peptide — a
molecular building block of cells — from the deadly substance.
They fed the peptide to termites and cotton bollworms, and
compared the effects with those of mealworms injected with the
peptide.

When ingested by insects, the poisonous chemical, called orally
active insecticidal peptide-1, was as toxic as the synthetic
insecticide imidacloprid, the group reported today (Sept. 11) in
the journal
PLOS ONE. A combination of the venom peptide and synthetic
insecticide was even more effective.

The venom was more potent against cotton bollworms than against
termites and mealworms, which eat stored grains rather than
crops, results showed.

Venoms from other insect-eating animals, such as centipedes and
scorpions, may also contain peptides that could be used as
bioinsecticides. Or, scientists could
genetically engineer insect-resistant plants or microbes that
produce these toxins.

"The breakthrough discovery that spider toxins can have oral
activity has implications not only for their use as
bioinsecticides, but also for spider-venom peptides that are
being considered for therapeutic use," study researcher Glenn
King of the Institute for Molecular Bioscience at the University
of Queensland, Australia, said in a statement.

S. plumipes is one of Australia's largest spiders, but
is not harmful to humans.